Abstract

The purpose of this study was to examine the relative contributions of physical and emotional functioning to overall quality of life (QOL) in men with heart failure (HF). In 76 men with HF (age 63 ± 11 years; left ventricular ejection fraction 27 ± 9%; 20% NYHA III/IV), initial correlations of Cardiac-Quality of Life Index (C-QLI) scores with sociodemographic/clinical variables, physical functioning (6-minute walk test and Heart Failure Functional Status Inventory), and emotional functioning (depression, anxiety, and hostility, as measured by the Multiple Affect Adjective Checklist) were followed by multivariate stepwise regression. After controlling for sociodemographic/clinical variables, younger age (variance=9%, P=.008), higher depressive symptoms (variance=16%, P=<.001), and lower self-reported physical functioning (variance=4%, P=.03) accounted for lower C-QLI scores (R2=0.33, P=.03). Compared with physical functioning, emotional functioning and younger age have a stronger relationship to QOL in men with HF.

Despite advances in the therapeutic management of patients with heart failure (HF), survival among these patients remains limited. Hence, evaluation of quality of life (QOL) has emerged as an important clinical outcome in HF.1–4 QOL is a multidimensional construct, which embraces a patient's level of productivity, the ability to function in daily life, the performance of social roles, intellectual capabilities, emotional status, and satisfaction with life.5

Limited physical functioning is recognized as an important and major component of QOL in patients with HF.1,2 Some studies, which have examined physical functioning and QOL in patients with HF, have yielded equivocal findings.3,4,6,7 Intervention studies designed to improve physical functioning in patients with HF have not shown a concomitant improvement in QOL.6,7 Other studies have shown improvement in QOL without improvement in physical functioning,4 while still others have found weak correlations between physical functioning measures and QOL scores.3 Together, these findings suggest that factors other than physical functioning or symptoms are related to a patient's report of QOL.

A key factor related to QOL in patients with HF is depression. Recently, the prevalence of depression8 and its relationship with a variety of clinical outcomes, such as functional decline,9 noncompliance to treatment recommendations,10 hospital readmissions,11 health care costs,12 and mortality rates,13 has been reported in the literature pertaining to HF. In patients with acute myocardial infarction, depressive symptoms are strongly predictive of a greater symptom burden, greater physical limitations, poorer QOL, and poorer overall health.14 Recently, similar associations of depression to QOL in HF patients have been reported.15,16

Recent reports suggest that men with HF face unique concerns related to QOL. A qualitative study of HF patients revealed that men experience more social isolation and loss, compared with women.17 In another HF study, physical symptom status was found to be associated with QOL in women, whereas, depression was related with QOL in men.18 These findings are consistent with those of other reports of men with chronic illness, which indicate that health, family, and relationship with a partner are important areas that are related to QOL.19 In a small study of men with HF who experienced erectile dysfunction, an intervention of Sildenafil improved sexual function and, consequently, QOL.20 While the separate relationships of both physical and emotional functioning to QOL have been documented in HF patients, what is not known is whether one form of limitation, physical or emotional, is more strongly associated with QOL than the other among men afflicted with HF. Thus, the objective of this study is to evaluate the relative association of physical functioning and emotional functioning with overall QOL in men with chronic HF.

METHODS

Design and Study Population

This was a secondary analysis of a prospective randomized controlled study of exercise in HF.21 The current report is a cross-sectional analysis of baseline data. The majority of patients were recruited from the VA Greater Los Angeles Health Care System. Patients with HF were included in the study if they: (1) were stable and ambulatory, (2) had a left ventricular ejection fraction ≤40% and an NYHA class II to IV, and (3) were without any orthopedic, pulmonary, and/or neurologic limitations to exercise.

Measures

QOL. Overall QOL was conceptualized as a multidimensional construct that accounts for an individual's perceptions of satisfaction with life in various broad domains (eg, physical functioning, socioeconomic status, psychological status, etc.).22 To correspond to this conceptualization, the Cardiac-Quality of Life Index (C-QLI) was utilized to measure QOL. The C-QLI, a 64-item questionnaire, measures “life satisfaction” as the main indicator of QOL on the following 4 subscales: (1) health function domain (activities of daily living [ADLs], social activities, symptoms, and sexual function); (2) socioeconomic domain (occupational capacity, education, and neighborhoods); (3) psychological/spiritual domain (sense of well-being, faith in God, and general satisfaction with life); and (4) family domain (relationships with family, friends, and/or significant others).23 It consists of 2 parts: (1) part I measures satisfaction with various domains of life and (2) part II measures the importance of the same domains to the subject.23 For scoring, the instrument uses a Likert scale from 1 (very dissatisfied/very unimportant) to 6 (very satisfied/very important).23 The scores were calculated by weighting each satisfaction response with its paired importance response and adding a constant of 15 to the averaged weighted items answered. The rationale for this weighting scheme is the belief that great satisfaction with highly important areas of life is related positively to QOL, whereas great dissatisfaction with highly important areas is related negatively.23 The scores range from 0 to 30. High scores result from the combination of high satisfaction and high importance responses; low scores result from the combination of high dissatisfaction and high importance scores. The overall C-QLI is the mean of all the weighted items. The subscale score is the mean of the discrete subsets of weighted items. The total C-QLI score and subscale scores were used for this study. The C-QLI has well-established validity23 and reliability23 in cardiac patients, including patients with HF. In this study, the mean and median scores of the total C-QLI and its 4 subscales, together with their psychometric properties, are shown in Table I.

Table I. Mean (SD) of QOL and Emotional State Instruments with Psychometric Properties

Instruments

Mean± SD

Median

Chronbach'sα

Cardiac-Quality of Life Index

Physical health functioning

17.2 ± 5.8

17.7

0.91

Psychological/spiritual functioning

20.5 ± 6.6

21.7

0.89

Socioeconomic domain

19.5 ± 5.6

20.0

0.84

Family functioning

22.3 ± 5.8

22.5

0.59

Overall

19.0 ± 5.1

18.9

0.79/0.94

Multiple Affect Adjective Checklist

Depression

10.9 ± 5.5

11.0

0.85

Anxiety

5.1 ± 3.6

5.0

0.77

Hostility

6.8 ± 4.3

7.0

0.85

Sociodemographic/Clinical Variables. A number of sociodemographic and/or clinical factors are related to QOL. Specifically, the variables of age, social support, body mass index (BMI), and ethnicity were considered.

Age. Advancing age is associated both with diminished QOL24 and increased incidence of HF.25 In fact, QOL is worse in elders with HF compared with their healthy peers.26 However, when only HF patients are considered, younger patients have worst QOL compared with elderly ones (>65 years).27 The contradictory nature of these previously reported data suggest that the relationship of age to QOL in HF is unclear. Age was measured as documented birth date.

Social Support. Changes in social support have been associated with changes in QOL among patients with HF.28 Bennett et al.28 indicated that younger men (<65 years) with HF reported lower social support compared with elderly men (≥65 years) and women in either age group. For our current study, the presence or absence of a significant other was used as a surrogate measure of social support.

Recently, additional factors have been found to be associated with QOL. BMI, expressed as weight in kg/m2, has been reported as an important predictor of QOL. Primary care patients with a BMI of 20 to 25 kg/m2 have optimal QOL scores.29 Obesity (BMI≥30 kg/m2) is associated with lower health-related QOL among patients≥45 years even after controlling for the presence of other comorbid conditions.30 Likewise, ethnicity is associated with QOL. In a study of prostate cancer patients, a comparison of non-Hispanic white men with other ethnic groups (ie, African American, Hispanic, etc.) revealed that ethnic minorities had lower QOL.31 Ethnicity was considered a potential intervening variable, which was dichotomized as Caucasian or non-Caucasian.

In summary, age, social support (ie, the presence of a significant other), BMI, and ethnicity were considered intervening variables. These data were obtained from initial interview and chart audit.

Physical Functioning. Performing ADLs is important for most HF patients. Thus, we selected baseline data (before randomization in the parent study) of 2 physical functioning measures that reflect daily functioning: (1) an objective measure: the 6-minute walk test (6-MWT), which is a submaximal exercise capacity test and (2) a subjective measure: the Heart Failure Functional Status Inventory (HFFSI),5 which is a self-report of daily physical functioning.

Six-MWT. The 6-MWT is a widely used exercise test to evaluate the physical functioning of patients with HF for a number of reasons. The 6-MWT, a submaximal exercise test, has been shown to have a moderate correlation with peak VO2 (r=0.54).32 The test has been shown to be sensitive to changes in clinical condition among patients with HF.33 More importantly, the 6-MWT test may closely reflect a HF patient's daily functional impairment than maximal exercise testing.34 In this study, patients were asked to walk in a flat, obstacle-free corridor from end-to-end at their own pace while attempting to cover as much ground as possible in the allotted period of 6 minutes. In 10% of the current sample, test-retest reliability yielded a correlation of 0.92 (P=.01).

HF Functional Status Inventory. The HFFSI, a 25-item self-administered questionnaire, quantifies a patient's assessment of overall daily activity performance.5 In each item, the patient indicates whether a particular ADL can be performed with a corresponding metabolic equivalents (MET) assignment by answering “yes,”“yes, but only slowly,” or “no, I can't do this.” Responses of “yes, but only slowly” or “no, I can't do this” were followed by questions that identified the major activity-limiting symptom (ie, dyspnea, fatigue, etc.). The final HFFSI score is the average of the 3 highest MET-level items performed by the patient. Scores range from an average of 2 to 7.8 METs. A panel of judges in cardiology determined the content validity of the tool.5 The internal consistency reliability was reported as an α coefficient of 0.84.35 In 10% of the current sample, the HFFSI test-retest reliability yielded a correlation of 0.92 (P=.01).

Emotional Functioning. The Multiple Affect Adjective Checklist (MAACL) was used to evaluate negative emotions of depression, anxiety, and hostility.36 At baseline, patients were asked to check all adjectives in the questionnaire that reflected how they felt at the time. It is a self-administered questionnaire with 132 adjectives in which 89 items measure anxiety (21), hostility (28), or depression (40).37 The remaining 43 items (adjectives) are not counted in scoring. From the 89 items, 45 adjectives are negative and 44 are positive. The scoring is bipolar, so that checking a negative adjective contributes a point toward the score and not checking a positive adjective contributes a point. Higher scores indicate greater dysphoria. A score ≥11, ≥7, and ≥7 indicate the presence of depression, anxiety, and hostility, respectively. Multiple reports have demonstrated the sensitivity, reliability, and validity of the instrument.38 The mean and median scores of MAACL depression, anxiety, and hostility with their psychometric properties are presented in Table I.

Procedure

The Institutional Review Board approved the protocol. In the outpatient setting, eligible patients were invited to enroll in the study. After giving informed consent, patients were asked to complete a questionnaire booklet that includes the above-described instruments. While completing the questionnaires, a trained nurse research assistant was available to assist the patients. Patients were free to leave items unanswered. At completion, the questionnaire items were checked to assure that the patient did not unintentionally leave any item blank. The duration of questionnaire administration ranged from 20 to 30 minutes. Then, the patient was asked to perform the 6-MWT. Immediately before the test, the nurse research assistant provides a scripted 6-MWT instruction. The principal investigator randomly checked for proper use of the 6-MWT script instruction. During the 6-MWT test, the research assistants were not allowed to talk to the patient. At the end of the 6-MWT, the distance walk was recorded in feet.

Statistical Analysis

Descriptive statistics were utilized to: (1) summarize the C-QLI total and domain scores and the MAACL dysphoria scores, (2) evaluate sample characteristics, and (3) to identify the top highest and lowest paired satisfaction and importance items of the C-QLI.

To determine the strength of the relationship of physical functioning and emotional functioning measures to overall C-QLI scores, 2 analyses were performed. First, a Spearman correlation was performed to identify sociodemographic variables (ie, age, significant others, BMI, and ethnicity), physical functioning measures (ie, 6-MWT and HFFSI) and emotional functioning measures (ie, MAACL depression, anxiety, and hostility) that were strongly correlated with the overall C-QLI score and domain scores. Finally, a multiple regression was performed. In the regression, significant sociodemographic and clinical variables (P≤.10) were entered first as a block, followed by a stepwise regression of physical and emotional functioning variables. The integrity of the resultant models was verified with a variance inflation factor (VIF), the principal multicollinearity diagnostics, with a recommended cutoff value <10.39 All analyses were performed using SPSS, version 13.0 (SPSS, Inc., Chicago, Illinois). All data were expressed as the mean ± SD or percent. Significance was set at P<.05.

RESULTS

The summary of the overall C-QLI scores, C-QLI subscale scores, and the MAACL emotional dysphoria scores are shown in Table I. For both depression and hostility, the median scores were at the cutoff for community norms of 11 and 7, respectively. The median score of 5 for anxiety was slightly lower than the community norm of 7.

A total of 76 men with HF were included in the study. The sociodemographic and clinical characteristics of the study sample are shown in Table II. The age distribution of the sample ranged from 33 to 81 years (mean: 63 years). Slightly fewer than half of the patients (N=36, 47%) were 65 years of age or older. Part-time employment was attained by only 20% of the sample, while the remainder were disabled, retired, or unemployed. While most indicated that they had a significant other, 18% reported they had no one to call on for help.

With regards to the C-QLI items, the top 10 most satisfying yet most important areas of life, as well as the top 10 lowest satisfying yet most important areas of life identified by the patients are shown in Table III. “Personal faith in God,” a psychological/spiritual subscale item, was the top-paired highest satisfaction/most important item score. “Health care received,” a health functioning subscale item, was the second most satisfying and most important paired item score. Conversely, “not having a job,” a socioeconomic subscale item, was the top-paired least satisfying, yet most important, area of life identified by these patients.

A correlation matrix of sociodemographic, clinical, physical, and emotional functioning variables, and the C-QLI total and subscale scores are presented in Table IV. The overall C-QLI scores and C-QLI subscale scores were more highly correlated with emotional functioning measures than with physical functioning measures. Depressed mood were highly correlated with each of the C-QLI subscales. Anxious mood was highly correlated with the C-QLI health functioning and psychological/spiritual subscales, whereas hostile mood was mostly correlated with the C-QLI psychological/spiritual subscale.

Taken individually, dysphoria scores of depression, anxiety, and hostility were each highly associated with the overall C-QLI scores (Table IV). Despite high correlations among the dysphoria scores, the VIF diagnostics indicated that multicollinearity did not threaten the final model.39 Because each of these emotional functioning variables is a unique concept, they were all entered in the final multivariate model. Similarly, there was a high correlation between the measures of physical functioning (6-MWT and HFFSI). Because each measure provides an objective and subjective view of physical functioning, both were included in the final model.

In the final stepwise regression, higher depression scores, younger age, and lower HFFSI scores were strongly associated with poorer overall C-QLI scores (Table V). As depression scores increased, the C-QLI index scores decreased (Figure 1A). On the other hand, older age was associated with better C-QLI scores (Figure 1B). In Figure 1C, lower HFFSI scores (perception of symptomatic ADLs) were mildly associated with worse C-QLI scores. To address the issue of multicollinearity among the emotional functioning variables, the strategy of including only 1 dysphoria variable at a time in sequential multivariate models was used.39 For each separate model, each dysphoria variable (depression, anxiety, and hostility) exhibited a greater percentage of the variance in the C-QLI score than did the sole physical functioning variable to enter the equation (HFFSI) as shown in Table V. Similarly, the strategy of including only 1 physical functioning variable (ie, the 6-MWT or HFFSI) at a time was employed to address the issue of multicollinearity. In this case, only the subjective measure of physical functioning (HFFSI) contributed to the variance of the C-QLI score (5%, β=0.21, P=.03).

DISCUSSION

This study provides 2 major unique contributions to the QOL literature in HF. First, our present study highlights a select group of HF patients with characteristics known to be associated with poor QOL outcomes. Compared with others, our sample is relatively young, primarily male, and likely to have fewer economic and social resources than patients recruited from many clinical settings. Thus, our findings shed light on the relationship of QOL to physical and emotional functioning in highly vulnerable, disadvantaged men with HF. Second, the C-QLI instrument has stronger criterion validity than do other measures of QOL frequently used in studies of HF patients.40 The C-QLI is not heavily weighted toward physical symptoms, as is the well-known Minnesota Living with HF questionnaire,41 or toward emotional symptoms. The instrument evaluates satisfaction with both internal and external factors associated with QOL, such as work capacity, family, social support, and socioeconomic status. Also, the psychological/spiritual domain of the C-QLI does not contain items related directly to the patient's affective state. Rather, it includes items related to a general sense of well-being. Additionally, the C-QLI includes the patient's rating of importance for each domain, so that our findings are individually referenced for each patient. Therefore, our findings reflect a unique balance of patient concerns related to satisfaction with life.

QOL and Emotional Functioning

Emotional functioning, specifically higher depression scores, explained a larger percentage of the variance in overall QOL than physical functioning among male Veterans with mild to moderate HF. Specifically, higher depression scores accounted for 17% of the variance in C-QLI scores compared with the 4% variance accounted for by the daily physical functioning measure, ie, HFFSI score. Compared with earlier reports in which physical functioning was most predictive of QOL specifically related to health,1 this study showed that emotional functioning, specifically depression, had a stronger relationship than physical functioning to overall QOL and life satisfaction among highly vulnerable male patients with HF. This is consistent with recent investigations reporting the significant association of depressive symptoms16 or major depressive disorder15 with lower QOL. Compared with women, Heo et al.18 reported that depression rather than physical symptom status was significantly correlated with QOL in men with HF. Moreover, our study findings correspond with the assertion of Smith et al.'s42 proposed model in which patients give greater emphasis to mental health than physical function in rating QOL.

In this sample of male Veterans with HF, “not having a job” (Table III) was identified as the topmost dissatisfactory/most important paired CQLI item score. In a sample of Veteran men without major illness (aged 35–60 years), Linn et al.43 reported that unemployment had a negative relationship to psychological function in which the unemployed became more anxious, depressed, and concerned with bodily symptoms compared with those who continued to work.43 As previously presented, slightly over half of our sample was less than retirement age (ie, <65 years). In Veterans with advanced cancer, higher psychological symptom of distress was associated with more unmet needs in the emotional/social, economic, and medical domains.44 This may explain our study findings, which indicate high correlations among the 3 affective states of depression, anxiety, and hostility, and the moderate correlations of each dysphoria score to overall C-QLI score. Furthermore, Kreitler et al.45 reported that the social index stressor (that includes unemployment) was negatively associated with overall QOL compared with health index stressor. Future studies should discern the meaning of unemployment relative to emotional functioning and/or QOL among men with chronic HF. In addition, future studies designed to test the relationship of unemployment-related distress and QOL through nursing interventions, especially among younger men with HF, are warranted.

Our results are parallel with other QOL investigations in patients with other chronic conditions.46–48 A recent study demonstrated that life dissatisfaction was determined by depressive symptoms rather than functional status or disease severity among patients with CAD.46 In a longitudinal study of MI patients, those with higher symptoms of depression and anxiety at baseline had a poorer QOL at a 1-year follow-up.47 In a large sample of patients with different chronic medical conditions (ie, hypertension, diabetes mellitus, lung disorders, heart conditions, rheumatoid arthritis, etc.), the domain of psychological functioning contributed to overall QOL.48

QOL and Physical Functioning

After “not having a job,” the most commonly identified least satisfying yet most important items were all from the C-QLI health functioning subscale items (Table III). Nonetheless, the variance contribution of physical functioning (ie, HFFSI) to overall QOL was lesser than emotional functioning. A likely explanation for this finding is that the relationship of physical functioning to overall QOL is dependent upon how the individual perceives or experiences physical limitations. This explanation is supported by Kreitler et al.45 who found that the relationship of the health index stressor to overall QOL was mediated by perceived stress among patients with cancer. This may also support our finding that the HFFSI (a subjective measure) significantly contributed to the variance of overall QOL compared with the 6-MWT (an objective measure) because only the HFFSI accounts for an individual's perception of his/her daily physical functioning.

For this sample of men with HF, “sex life” was the topmost dissatisfied/important C-QLI health-functioning subscale item (Table III). Freitas et al.[20] reported that improved erectile dysfunction following Sildenafil administration was associated with improved QOL among men with HF. Perceptibly, “sex life” is an important daily activity that affects QOL among men with HF. Future studies should explicate the strength and magnitude of the relationship of sexual dysfunction to depression and/or overall QOL in men with HF.

QOL and Age

Our findings reveal that age and QOL are inversely related and that age is a better indicator of QOL than physical functioning. Other studies also indicate that individuals aged 50 to 75 endorse higher QOL than younger individuals.49 Investigators argue that the inverse relationship of age with QOL arises from the likelihood that the young retain greater expectations of life than their older peers and that older individuals have acquired adaptation and resilience that supports positive QOL.49 The current finding that age is a stronger correlate of QOL than physical functioning is consistent with the finding that age and QOL are inversely related. With a mean age of about 63 years, our population falls within what is becoming known as the “third age” when individuals are exiting the work force, but before extreme physical dependency has emerged.49

Limitations

Our present study has a number of limitations; therefore, our findings should be interpreted with caution. First, we measured self-reported depression and did not evaluate the presence of clinical depression. Nonetheless, our findings regarding the positive relationship of depressed mood and overall QOL are germane because depressive symptoms, even in the absence of a clinical disorder, have been shown to have predictive value for mortality and morbidity in cardiac patients.13 However, further study is warranted to assess the relationship of clinical mood disorders to overall QOL with the use of established instruments that are consistent with current diagnostic criteria. Finally, the findings were also limited by the small sample size and the rather homogeneous nature of our sample, which consisted primarily of younger male patients with systolic dysfunction. Future studies with a larger, more diverse sample, including women and men, as well as older HF patients, will help to further elucidate the explicit relationships of all the variables included in this model.

Conclusion

Our findings suggest that the association of physical role limitations to overall QOL in patients with HF has been overemphasized. This study demonstrates that emotional dysphorias (particularly, depression, anxiety, and hostility) are associated with overall QOL in male HF patients than does physical functioning. The importance of this relationship is underscored by increasing reports of the high prevalence and adverse consequences of depression in patients with HF.8,11,12,50 To improve QOL in patients with HF, routine clinical assessment of depression and anxiety is needed in conjunction with assessment and management of symptoms and physical functioning symptoms. In addition, it will be worthwhile for future research investigations to understand the implication or magnitude of the relationship of unemployment and or sexual dysfunction to either emotional dysphorias and/or QOL especially among younger men afflicted with HF.

Acknowledgments

Acknowledgment: This study was supported by the Veterans Administration HSR&D: Nursing Research Initiative #96.031.1.

16Muller-Tasch T, Peters-Klimm F, Schellberg D, et al. Depression is a major determinant of quality of life in patients with chronic systolic heart failure in general practice. J Card Fail. 2008;13:818–824.